Peripheral nerve injuries

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					Peripheral nerve injuries

Diabetes Mellitus

Effect of diabetes on LUT
 Neuropathy is present in < 10% when diabetes is

discovered.  Autonomic and peripheral nervous system dysfunction can occur in 20% – 50% of diabetic patients.  There is no correlation between the type, duration of diabetes or the age of the patient and bladder affection.
 Bladder dysfunction is related to the severity of diabetes and not to

its duration.

 80% of patients with diabetic cystopathy have other

significant diabetic sequelae.

Effect of diabetes on LUT
 Isolated autonomic neuropathy is rare and mixed form is

common.  Decreased superficial and deep sensations in lower limbs and peri-anal region.  Diminished knee jerks, ankle jerks or bulbocavernosus reflex.

Effect of diabetes on LUT
 In diabetes somatic and autonomic

neuropathy generally exist concurrently.  Diabetes affect mainly the bladder.  The external sphincter might be affected if there is concomitant somatic neuropathy (severe pudendal neuropathy).  Vascular complications affecting the brain or spinal cord will lead to overactive bladder.MCI

The mechanism of LUT dysfunction
 Sensory afferent pathways affected first  Impaired bladder sensations  Increase interval between voidings

Timed voiding

 Detrusor over-distension and impaired contractility
 Increased residual urine and low flow.

 Chronic retention and overflow incontinence.

Urodynamic findings
1. Elevated residual urine.
2. Impaired bladder sensations. 3. Increased cystometric capacity and hypercompliance. 4. Decreased bladder contractility. 5. Involuntary detrusor contractions. Due to cortical or

spinal regulatory tracts affection.

Limitation of urodynamics in D.M and BPH
Decompensated (Underactive) bladder  We can not tell by P/F study whether the prostate is obstructing or not----Video-urodynamic, Sofisticated UD Tests or cystoscopy.  Some surgeons recommend bladder neck resection in diabetic cystopathy even in absence of BOO.  So, if there is obstructing adenoma by cystoscopy, it should be removed.

Fate after surgery
 In case of impaired detrusor contractility, patients

can empty their bladder after surgery by: 1. Chlonergic drugs (limited role). 2. Crede and Valsalva. 3. CIC (primary mode of treatment).

Guillain- Barre syndrome.

 Immune mediated disease affecting small and large meylinated

axons causing acute progressive weakness, usually an ascending paralysis.

Pathology and pathogenesis
 30% have respiratory paralysis necessitating mechanical
    

ventilation. Complete recovery is the rule. Autonomic neuropathy occur in 50% of cases. Micturition symptoms in 25% of patients. Storage and emptying functions are affected. There may be irritative or obstructive symptoms.

Pathology and pathogenesis
 Usually pelvic plexus and its associated nerves

(sympathetic and parasympathetic) are responsible for LUT dysfunction.  Urodynamic parameters improve during the course of disease in 6-8 weeks after the onset of weakness.  Full or significant recovery is expected.

LUT dysfunction
 Bladder dysfunction is either:

1. Bladder areflexia, impaired sensations and large

residual. 2. Detrusor hyper-reflexia with or without sphincter dyssynergia. Over-activity occur at the peripheral nerve level with probable pelvic nerve irritation (there is no radiological affection of spinal cord).

Cauda Equina Syndrome (CES)
 Cauda equina is the part of nervous system below the level

of conus medullaris within the spinal cord.  It consists of both sensory and motor nerves.

Clinical presentation
 Low back pain.

 Sciatalgia.
 Saddle and peripheral hypoethesia.  Decreased anal tone, absent ankle, knee or

bulbocavernosus jerks.  Variable lower limb motor and sensory loss.  Bowel and bladder dysfunction

LUT dysfunction
 Disturbance in emptying including (underactive or

acontractile bladder):  Acute urine retention, voiding by straining, poor stream.  Overflow incontinence is the second most common presentation.  Fecal incontinence due to decreased anal tone (most common) or constipation.

Bladder decenralization
 Bladder decentralization is LMNL occurs in

myelodysplasia, CES and radical pelvic surgery.  Areflexic, hypotonic or flaccid bladder and denervated urethral sphincter.  Preservation of the sphincter can sometimes occur because the dominant segment of the pelvic nerve arise one segment higher than that of pudendal nerve.

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